Oil recovery process by miscible displacement
This invention involves a process for displacement and recovery of reservoir oil by injecting a bank of polar organic solvent, a second bank of surfactant, organic additive and water, and a following bank of floodwater to drive the fluids through the formation to the producing well. The preferred polar organic solvent is tertiary amyl alcohol but other similar solvents may be employed as long as they have a relatively high molecular weight and are preferentially oil soluble. The surfactant favored has a relatively low molecular weight and is sodium xylene sulfonate, in aqueous solution. Methanol is the preferred organic additive, but other alcohols may be used as well as amines, ketones, aldehydes, and organic acids. The organic additive is chosen for its ability to lower the density of the aqueous surfactant bank thereby reducing the tendency of the second bank to underride the first bank. It also reduces the quantity of surfactant necessary for multi-bank displacement. Polymeric thickeners may be used in aqueous solutions to improve the mobility ratio between the sulfonate bank and the solvent bank it displaces.
- Assignee:
- Esso Production Research Co.
- Patent Number(s):
- US 3605891
- OSTI ID:
- 7299589
- Country of Publication:
- United States
- Language:
- English
Similar Records
Miscible displacement process using modified alcohol banks
Two-bank miscible tertiary oil recovery process